1-bromo-2-methylbutane

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: Two, 2-amino-4-methylhexanoic acid (homoisoleucine, Hil) units were identified after analyzing the PS (phase sensitive) DQF COSY and TOCSY spectra of vitilevuamide. The stereochemistry of the amino acids was confirmed by chemical synthesis of all four diastereomers, and evaluation of the 1-fluoro-2,4-dinitrophenyl-5-L-alanineamide (FDAA; Sigma Chemical Co., St. Louis, Mo.) derived amino acids by HPLC on a cyano column. The mixtures of (2RS,4S) and all four isomers of Hil were synthesized starting from S-(+) and (±)-1-bromo-2-methyl butane (Sigma Chemical Co. or Aldrich Chemical Co., Milwaukee, Wis.) respectively using the method of H. Han & R. A. Pascal, 55 J. Org. Chem. 5173 (1990). The diastereomeric mixture of (2RS,4S)-2-amino-4-methyl hexanoic acid was treated with catalase and L-amino acid oxidase (Aldrich Chemical Co.) at pH 8 for 12-18 hours. Upon acidification and reverse phase chromatography (9:1, MeOH/H2O), the pure (2R,4S) isomer of Hil was isolated. Using these standards it was possible to verify the stereochemistry of the two Hil residues in vitilevuamide by FDAA derivatization and cyano HPLC chromatography (MeOH/1% Acetic acid, 25:75-90:10 at 1 mL/min) with UV detection at 340 nm. The mixtures of (2RS,4S) and all four isomers of Hil were synthesized

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 0.20 mole(37.2 g) of 4,4'-dihydroxybiphenyl, 0.10 mole(15.1 g) of the above 2-methyl-1-bromobutane, and 0.60 mole(33.7 g) of potassium carbonate in 300 ml of ethanol was refluxed for 16 hours. After the reaction, the reaction solution was filtered and concentrated, then purified by column chromatography to obtain 4.9 g of 4'-(2-methylbutoxy)-4-hydroxybiphenyl. (yield: 58%) After the reaction the reaction solution was filtered concentrated purified by column chromatography

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4,4'-dihydroxybiphenyl (500 g), ethyl alcohol (7.5 l) and potassium hydroxide (302 g) was heated with stirring under reflux, and (+)-2-methylbutylbromide (prepared from (-)-2-methylbutanol and phosphorus bromide) (530 g) was dropwise added to carry out reaction for 4 hours, followed by distilling off ethanol, adding water (2 l), filtering, collecting insoluble matter, adding toluene to this insoluble matter to dissolve and remove toluene-soluble matter (this soluble matter, when recrystallized from ethyl alcohol, gave scaly crystals having a m.p. of 80.5° C.; thus the compound was confirmed to be 4,4'-di((S)-2-methylbutyloxy)biphenyl), heating the insoluble matter together with 3N-hydrochloric acid with stirring, cooling solid matter and recrystallizing from toluene and then from ethyl alcohol to obtain 4-hydroxy-4'-((S)-2-methylbutyloxy)biphenyl (XXI) having a m.p. of 137.5° C. (125 g). was heated under reflux reaction for 4 hours by distilling off ethanol adding water (2 l) filtering collecting insoluble matter adding toluene to this insoluble matter to dissolve remove toluene-soluble matter (this soluble matter, when recrystallized from ethyl alcohol gave scaly crystals with stirring cooling solid matter recrystallizing from toluene

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 4,4'-dihydroxybiphenyl (500 g), ethanol (7.5 l) and KOH (302 g) was heated under reflux with stirring, and (+) 2-methylbutyl bromide (prepared from (-)2-methylbutanol with phosphorus bromide)(530 g) was dropwise added for 4 hours to react them, followed by distilling off ethanol, adding water (2 l), filtering, collecting an insoluble substance, and treating this insoluble substance with toluene to remove a soluble substance. This soluble part was recrystallized from ethanol to give scaly crystals of m.p. 80.5° C., which was confirmed to be di-(2-methylbutyloxy)-biphenyl. On the other hand, the above insoluble part was heated together with hydrochloric acid with stirring, followed by cooling, collecting the resulting solid substance and recrystallizing it from toluene and then from ethanol to obtain 4'-(2-methylbutyloxy)-4-hydroxybiphenyl of m.p. 137.5° C. (125 g). was heated under reflux to react them by distilling off ethanol adding water (2 l) filtering collecting an insoluble substance treating this insoluble substance with toluene to remove a soluble substance This soluble part was recrystallized from ethanol to give scaly crystals of m.p. 80.5° C., which with stirring by cooling collecting the resulting solid substance recrystallizing it from toluene